Tarantino is an artist, backed by patrons Bob and Harvey Weinstein, who has routinely turned down big-studio directing gigs in order to pursue his own muse. And he can be sensitive to the slings and arrows of public opinion. That’s because he wants to leave a meaningful cinematic legacy of just 10 films. So while he could always change his mind (as Steven Soderbergh did) about his career path, Tarantino does not take lightly his choice of what those last two films will be. (The last one might be “Kill Bill: Vol. 3,” if a Bonnie and Clyde in 30s Australia project has been set aside.)

“Hopefully, the way I define success when I finish my career,” he told the 2016 Adobe Max conference, “is that I’m considered one of the greatest filmmakers that ever lived. And going further, a great artist, not just filmmaker.”

The filmmaker was gobsmacked when an early draft of “The Hateful Eight” leaked online, so much so that he (briefly) bailed on the western before getting back on track. Like most of his movies, “The Hateful Eight” has more to do with putting colorful, dialogue-spewing characters into a stylized universe inspired by classic Hollywood movies than anything related to the real world. That claustrophobic homage to “The Petrified Forest” and “Key Largo,” where a group of strangers trapped in a contained space need to figure out who the others are in order to survive, contained references to everything from “Gone with the Wind” to “Rio Bravo.”

Much like his revered fellow dialogue maestro Aaron Sorkin, Tarantino starts with characters and lets them talk. He writes in longhand with black or red Bic or Flair pens in a white-paged notebook. Usually, he lets his characters lead him to their various denouements. With the sprawling scripts for “Django Unchained” and “Inglourious Basterds,” “I’d get to the third act,” he once told me. “That, I try never to maneuver. By the time it gets to the end, I was open to the characters to drive it. What the characters dictated, that’s what happened.”

So telling a story with an historic record is a radical departure for Tarantino. It’s unknown what, if any, source materials form the basis of the Manson movie; Tarantino has only adapted other people’s work once, when Elmore Leonard’s “Rum Punch” became “Jackie Brown.” While “Basterds” featured embellished supporting roles for Hitler and Joseph Goebbels, this would mark his first foray into a film with main characters from the real world, including Charles Manson and the four members of his Manson family who on August 8, 1969 murdered five people pregnant actress Sharon Tate, the wife of director Roman Polanski, in their Benedict Canyon home. Manson and his followers were sentenced to life in prison in 1971.

Tarantino presumably became fascinated by the Mansons over the past four years while he was researching the ’70s for a possible documentary. That doesn’t mean we can expect documentary verisimilitude from this movie. Tarantino has always been a daring form-buster, whether locking characters into a single room to see what combusts (“The Hateful Eight”), using four languages in “Inglourious Basterds,” or throwing out narrative conventions with chapters, radical changes in style inside a movie, or various voiceover cues from unexpected sources. If he wants to pay homage to ’70s movies, bring it on.

The other possibility is that Tarantino wants to get serious. The filmmaker craves respect and admiration, but his love for exploitation cinema hasn’t exactly enhanced his clout as a prestige director; in many ways, his brand is still associated with the early nineties efforts that put him on the map.

In any case, it seems likely that he has found a promising angle on the material, or else he wouldn’t bother. “I go where the character and scenario takes me,” he once told me. “With ‘Kill Bill,’ I started to write a female martial-arts revenge movie, but that’s not what came out. With ‘Reservoir Dogs,’ I wanted to write the best heist film ever and you never saw the heist. With ‘Inglourious Basterds,’ I enjoy the war-mission subgenre but I want to forward it, make it bigger, broader, more artistic.”

Inevitably, ’70s movies and music will be part of the fabric of whatever this film turns out to be. (Brad Pitt, Jennifer Lawrence and Margot Robbie are being floated as potential cast members.) Tarantino had asked Ennio Morricone to score his next film, as well — assuming he goes ahead and makes the movie, which the Weinsteins were reportedly just about to shop to potential partners. If Tarantino lands big names for his cast, he’ll be able to go off the beaten path with the aid of a bigger budget — and he’s one of only a few working filmmakers who never compromises, no matter what’s at stake.